Palma, Refael
Prentice-Hall, 1949
Buku Teks SO
Coates, Austin
Oxford University Press, 1968
Buku Teks SO
edited by M. Rajaretnam
Institute Kajian Dasar, 1996
Buku Teks SO
Dita Putri Prameswari
Universitas Indonesia, 2011
UI - Tesis Open
Burgess, Peter H.
Graham Brash, 1983
Buku Referensi